Method of setting write conditions for optical recording media

Abstract

A method is provided to enable efficient optimization of write pulse waveforms using a trial writing region. To record information on an optical recording medium using a laser beam, the method includes: recording a specific pattern of multiple record marks on the trial writing region of the optical recording medium; decoding a read signal from the specific pattern using a PRML detection method; and tuning a write pulse waveform for forming the record marks based on the quality of decoded data determined by the PRML detection method.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a method of setting write conditions for optical recording media, and in particular, to a method of determining an optimum recording condition by trial writing on an optical recording medium. [0003] 2. Description of the Related Art [0004] Conventionally, various standard types of media such as CD-R / RWs or DVD-R / RWs have been widely used as optical recording media on which users can record information. In recent years, there has been growing demand for optical recording media of these types with higher storage capacities. To meet the demand, a new type of medium such as the Blu-ray Disc (BD) has also been suggested. According to an optical disc apparatus for Blu-ray Discs, the laser beam for reading or writing data thereon has a reduced beam spot diameter. More specifically, the laser beam is reduced in its wavelength λ and is condensed through an objective lens having an increased n...

AI Technical Summary

Benefits of technology

[0012] As a result of intensive studies by the inventor, it has become apparent that write pulse waveforms can be efficiently tuned even for recording at high speeds and high densities.

[0023] As describe above, the present invention advantageously allows efficient tuning of write pulse waveforms even during recording at such a high density that binary levels would not otherwise readily be discriminated by a slice level.

Problems solved by technology

However, an increase in recording rate with increased storage densities results in edge shifts occurring on record marks.

Additionally, when longer record marks such as those of 4T or 6T are formed using a plurality of write pulses, excessively high recording rates could fail to provide a sufficient length of time for cooling between write pulses.

As a result, the leading edge pulse or the trailing edge pulse could cause recrystalization due to insufficient cooling.

This recrystalization can also cause edge shifts.

This increases the time required for trial writing as well as requiring a larger region for trial writing.

An increase in storage density causes degradation in the quality of read signals, thereby making it difficult to determine bits by slice detection.

Thus, simply recording marks of all lengths as trial writing, as was conventionally done, would fail to provide sufficiently tuned pulse waveforms.

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